Micro-electromechanical systems (MEMS) devices have a wide variety of applications and are prevalent in commercial products. One type of MEMS device is a MEMS radio frequency (RF) switch. A typical MEMS RF switch includes one or more MEMS switches arranged in an RF switch array. MEMS RF switches are ideal for wireless devices because of their low power characteristics and ability to operate in radio frequency ranges. MEMS RF switches show their promising applications in cellular telephones, wireless computer networks, communication systems, and radar systems. In wireless devices, MEMS RF switches can be used as antenna switches, mode switches, and transmit/receive switches
However, a problem frequently occurs with MEMS RF switches. MEMS switches typically suffer from a problem where an actuation electrode within the switch may actuate at the “OFF” state (self-actuation) due to the high voltage RF signal. Thus, the high voltage RF signal produces adequate electrostatic force to pull down the switch beam and cause failure.
A MEMS switch may also encounter additional insertion loss (IL) through the actuation electrode/capacitor to ground due to capacitance coupling, which strongly downgrades the device's RF performance (e.g., from 0.3 dB to >1 dB).